The effect of TiC transient layer on a DLC-based functionally gradient coating prepared by closed field unbalanced magnetron sputtering plating system

Abstract

Recently, Diamond like carbon (DLC)-based functionally gradient coatings have been used in a variety of engineering applications as useful films with appropriate tribological properties verified in many tests. However, due to their inherent residual stresses, they have a tendency to peel off, thereby limiting their applications (involving high contact stresses) and deposition thickness. Their brittleness and low adhesion may stem from either a faulty layer design or the wrong choice of material and deposition method. Therefore, using both a suitable interleaving material and an appropriate deposition technology will create an inclusive vision to accommodate better film properties. In this study, Ti-a:C and Ti-TiC-a:C films on AISI M2 steel substrates were deposited by Closed Field Unbalanced Magnetron Sputtering (CFUBMS) method using pulsed-dc biasing, and the mechanical, the structural, and the tribological properties for both films were investigated. It was seen that the incorporation of a TiC buffer layer between the Ti interlayer and the a:C matrix played a positive role in terms of hardness, wear rate, and adhesion properties.

Adhesion Studies of CrC/a-C:H Coatings Deposited with Anode Assisted Reactive Magnetron Sputtering Combined with DC-Pulsed Plasma Enhanced Chemical Vapor Deposition

“…To obtain a hard and wear resistant metal carbide interlayer, high ion current densities at the substrates were necessary. Usually closed field unbalanced magnetron sputter (CFUBMS) technology [ 18 , 19 , 20 , 21 ] is employed to prevent electric escape and improve the ionization rate of sputter atoms. In addition, an innovative method to improve the ionization rate is to use the central anode developed by Wolf-Dieter Münz [ 22 ], by which the sputtering DLC coatings with 40–55 GPa hardness and low friction in the 0.05–0.07 range, were deposited onto threefold rotated stainless-steel substrates.…”